Pressure sensitive laminate

ABSTRACT

A pressure sensitive laminate comprising a backing sheet and a coating consisting of a profusion of capsules, each capsule containing a material, such as a liquid material, capable of marking a certain color. The capsules are constructed so that they will rupture in response to the application of a predetermined compressive pressure and when ruptured will release the marking material therein. All of the capsules containing a marking material of the same color will rupture at the same pressure, and capsules containing marking material of different colors will rupture at different pressure, thereby enabling marking of a part which is used to apply pressure to the laminate to indicate areas of varying pressure on the part.

United States Patent Hayes, Jr. et a1. Mar. 7, 1972 [54] PRESSURE SENSITIVE LAMINATE 3,249,458 5/1966 Cornell et al. ..117/122 P [72] Inventors: Edward J. Hayes, Jr.; Brian Hayes, both Primary Examiner Morris Sussman of 1801 Arlington Blvd., Ann Arbor, Mich. 48104 Attorney Olsen and Stephenson [22] Filed: Aug. 19, 1969 ABSTRACT [21] APP] No: 851,335 A pressure sensitive laminate comprising a backing sheet and V a coating consisting of a profusion of capsules, each capsule containing a material, such as a liquid material, capable of [52] US. Cl ..ll7/36.7, 1 17/152, 161/ 162 marking a certain color. The capsules are constructed so that [51] Int. Cl ..B41m 5/00 they will rupture in response to the application of a predeter- [58] Field of Search ..l 17/ 122 PA, 68.5, 36, 36.7; mined compressive pressure and when ruptured will release 161/167, 162 DIG 1 5 the marking material therein. All of the capsules containing a marking material of the same color will rupture at the same [56] References Cited pressure, and capsules containing marking material of different colors will rupture at different pressure, thereby UNITED STATES PATENTS enabling marking of a part which is used to apply pressure to the laminate to indicate areas of varying pressure on the part. 2,907,682 10/1959 Eichel ..117/122 P 3,138,515 6/1964 Dritz ..161/158 1 Claims, 5 Drawing Figures PATENTEDHAR '7 I972 3,647. 504

INVENTORS EDWARD J. HAYES JR. BRIAN J. HAYES 1 v v ATTORNEYS PRESSURE SENSITIVE LAMINATE This invention relates generally to pressure sensitive laminates, and more particularly to an improved laminate which incorporates capsules containing marking material. A liquid material is illustrated in the preferred embodiment but it is to be understood that other suitable marking materials can also be used.

Marking sheets adapted to be placed between two parts which are compressed together and which will mark the areas of one or more of the parts subjected to the highest pressure are well known. For example, such sheets are commonly used by dentists in fitting teeth which normally engage when the mouth is closed. However, the sheets now in common use for this purpose only mark the area of highest pressure. Consequently, repeated fitting of the parts with the marking sheet therebetween is required in order to finally achieve a shaping of the parts so that when they are moved together a uniform pressure is applied therebetween. It is an object of this invention, therefore, to provide an improved marking material of this type which is capable of indicating on the parts areas of varying pressures.

In the improved pressure sensitive laminate of this invention, a backing sheet is coated on at least one side with a coating consisting of a profusion of minute capsules. Each of the capsules consists of a continuous wall of a rupturable film forming material within which is retained a liquid marking material. The wall of each capsule is rupturable in response to the application of a predetermined compressive pressure on the laminate, and the capsules containing marking material of the same color are all rupturable at the same pressure. The liquid marking materials are of a plurality of colors and each capsule has a material of a single color therein. As a result, since capsules of all colors are uniformly dispersed in the coating, on application of varying pressures to different areas of the coating different colors of marking material will be released from those areas to effectively mark a part, such as a die, being tested so that the die can readily be finished to the desired contour.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIG. 1 is a perspective view of the pressure sensitive laminate of this invention;

FIG. 2 is a diagrammatic sectional view of a pair of irregularly contoured die members with the pressure sensitive laminate of this invention positioned therebetween;

FIG. 3 is a view of one of the dies shown in FIG. 2, as seen from substantially the lines 33 therein, illustrating the areas with different colored markings thereon following use of the laminate of this invention;

FIG. 4 is an enlarged fragmentary transverse sectional view of the laminate of this invention as seen from substantially the line 4-4 in FIG. I; and

FIG. 5 is a sectional view of a capsule in the coating which forms a part of the laminate of this invention.

With reference to the drawing, the pressure sensitive laminate of this invention, indicated generally at 10, is illustrated in FIG. I as consisting ofa backing layer 12 and a coating layer 14 which is secured to one side of the backing layer 12. The backing layer I2 can consist of any suitable paper, fabric or similar material, capable of retaining its shape and supporting the coating 14. The coating 14 consists of a profusion of minute capsules 16 (FIG. 4) which are uniformly applied to the backing layer 12 and are suitably adhered thereto I by a suitable binder 18. Each of the capsules 16 consists of a continuous wall 20 (FIG. 5) formed of a rupturable film forming material within which is retained a liquid marking material 22. The wall 20 for each of the capsules 16 is rupturable in response to the application of a compressive pressure of predetermined magnitude to the laminate 10.

The capsules 16 are formed so that the walls 20 are of varying thicknesses. As a result, some of the capsule walls 20 will rupture at a first pressure, a second group of capsules I6 are constructed so that the walls 20 will rupture at another and greater pressure, a third group of capsules I6 are constructed so that the walls 20 will rupture at still another and even greater pressure, and so on, depending upon the desired number of pressure variants to which the laminate I0 is to be sensitive. Each group of capsules 16 having walls 20 formed of similar thickness, so that they will rupture at the same pressure, contain marking material 22 of the same color. It is preferred that the capsules which rupture at the higher pressures will have darker marking material 22 therein. The capsules from the various pressure groups are uniformly dispersed in the coating 14 so that in any given area of the coating 14 all groups are uniformly represented.

In the use of the pressure sensitive laminate l0, assume that a die member 22 (FIG. 2) is to have its surface 24 contoured so that it will mate with a surface 26 on a mating die 28. The laminate 10 is disposed between the die surfaces 24 and 26 and the dies 22 and 28 are moved together under pressure. The die surfaces 24 and 26 are then moved apart, the laminate 10 is removed, and the surface 24, shown in FIG. 3, is examined. In the example shown in FIG. 3, the surface 24 is now provided with seven distinct colored surface impressions. By way of example, assume that the laminate 10 had three different groups of capsules 16, the group that will rupture at the lowest pressure containing marking material 22 colored white, another group containing orange marking material 22 being constructed for rupture at a higher pressure and another group containing black marking material 22 which will rupture at an even greater pressure. In this case, assume that the areas on the die surface 24 indicated at I, 3 and 5 are colored white, that the areas indicated at 2, 4 and 6 are colored orange, and that the area indicated at 7 is colored black. This immediately indicates that in order to obtain a desired fit the greatest amount of material will have to be removed from the area indicated at 7 and smaller amounts of material will have to be removed from the areas indicated at 2, 4 and 6. This enables the contouring of the surface 24 to the desired final contour with a minimum of testing. It is to be understood that this illustrated example is only one of the possible uses of the pressure sensitive laminate l0.

From the above description it is seen that this invention provides an improved pressure sensitive laminate 10 consisting of a backing layer 12 and a coating layer I4. A profusion of minute capsules I6 containing different colored marking material 22 constitutes the coating I4, the capsules 16 being constructed so that those containing marking material of the same color will rupture at the same pressure. As used herein the term minute" is inclusive of a size range of from several microns to several millimeters, measuring the largest dimension of a capsule. In each laminate 10, the capsules 16 are all of substantially the same size so that the coating I4 will be of uniform thickness. This enables use of the laminate 10 for a variety of purposes wherein varying pressures are significant.

We claim:

I. A pressure sensitive laminate comprising a backing sheet and a coating on at least one side of said sheet, said coating consisting of a profusion of minute capsules, each of said capsules consisting of a continuous wall of a rupturable film-forming material within which is retained a marking material, each of said walls being rupturable in response to the application of a predetermined compressive pressure on said laminate, said marking material being of a plurality of colors and each of said capsules having a material of a single color therein, said predetermined rupture pressure being the same for all capsules containing a marking material of the same color and said rupture pressure being different for capsules containing materials of different colors, each one of said capsules being disposed in said coating adjacent a containing a marking material of a color different from the color of the material in said one capsule, whereby on application of a lesser pressure to one area of said coating only said capsules rupturable at said lesser pressure would be ruptured and in an area wherein a predetermined greater pressure is applied all capsules con- IIIIII76 taining different colors would be ruptured, so that the resultant of different colors would be an indication of lower and higher areas of pressure applied to said pressure sensitive laminate.

- 2 3 UNITED STATES PATENT GFFICE CERTIFICATE OF CORRECTEGN Patent No. 3, 647, 504 v Dated March 7, 1972 Inventor(s) 1 Edward J'.- Hayes, Jr. arid Brian Hayes It is certified that error appears in the above-ideotified patent and that said-Letters Patentare hereby corrected as shown below:

Col. 2, linev70, Claim 1 before "confaining" insert capule I 1 Signed and sealed this 22nd day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTT SCHALK Attestlng Officer I Commissioner cf Patents 

